Fig. 8

Cumulative dLOS observed from a path 131 and b path 23. Symbols shown in a and b, such as the circles and rectangles, indicate the same information as in Fig. 6. Larger inset rectangles in a and b indicate displayed area of Fig. 6c, d correspond to the dLOSs time series of a and b at peak A (the red circle) and peak B (the blue circle). The vertical bars with the red and blue circles indicate the standard deviation of the estimated dLOS. Positive values in c and d correspond to ground motion toward the satellite. Solid, dashed and dotted lines indicate the timing of the phreatic eruption on April 19, 2018, the timing of the mud eruption from the fumarole vent A on April 26, 2017, and the acquisition date of the Pi-SAR-L2 data (1st, 2nd and 3rd). Around the day of the mud eruption, the dLOSs speed at the inflation peak during 2016–2018 exceeded (c) or reached (d) that at the inflation peak during 2014–2016